Cleanup timeline stream enabled flag so that it can be easily tested from an intrinsic

runtime/vm/thread.cc

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/thread.h"
 
 #include "vm/compiler_stats.h"
 #include "vm/dart_api_state.h"
 #include "vm/growable_array.h"
 #include "vm/isolate.h"
 #include "vm/lockers.h"
 #include "vm/log.h"
 #include "vm/message_handler.h"
 #include "vm/native_entry.h"
 #include "vm/object.h"
 #include "vm/os_thread.h"
 #include "vm/profiler.h"
 #include "vm/runtime_entry.h"
 #include "vm/stub_code.h"
 #include "vm/symbols.h"
 #include "vm/thread_interrupter.h"
 #include "vm/thread_registry.h"
+#include "vm/timeline.h"
 
 namespace dart {
 
 
 DECLARE_FLAG(bool, trace_service);
 DECLARE_FLAG(bool, trace_service_verbose);
 
 
 Thread::~Thread() {
   // We should cleanly exit any isolate before destruction.
@@ skipping 23 matching lines @@
 
 #define REUSABLE_HANDLE_INITIALIZERS(object)                                   \
   object##_handle_(NULL),
 
 
 Thread::Thread(Isolate* isolate)
     : BaseThread(false),
       stack_limit_(0),
       stack_overflow_flags_(0),
       isolate_(NULL),
+      dart_stream_(NULL),
       heap_(NULL),
       top_exit_frame_info_(0),
       store_buffer_block_(NULL),
       vm_tag_(0),
       task_kind_(kUnknownTask),
       os_thread_(NULL),
       thread_lock_(new Monitor()),
       zone_(NULL),
       api_reusable_scope_(NULL),
       api_top_scope_(NULL),
@@ skipping 13 matching lines @@
       cha_(NULL),
       deopt_id_(0),
       pending_functions_(GrowableObjectArray::null()),
       sticky_error_(Error::null()),
       compiler_stats_(NULL),
       REUSABLE_HANDLE_LIST(REUSABLE_HANDLE_INITIALIZERS)
       REUSABLE_HANDLE_LIST(REUSABLE_HANDLE_SCOPE_INIT)
       safepoint_state_(0),
       execution_state_(kThreadInVM),
       next_(NULL) {
+  dart_stream_ = Timeline::GetDartStream();
+  ASSERT(dart_stream_ != NULL);
 #define DEFAULT_INIT(type_name, member_name, init_expr, default_init_value)    \
   member_name = default_init_value;
 CACHED_CONSTANTS_LIST(DEFAULT_INIT)
 #undef DEFAULT_INIT
 
 #define DEFAULT_INIT(name)                                                     \
   name##_entry_point_ = 0;
 RUNTIME_ENTRY_LIST(DEFAULT_INIT)
 #undef DEFAULT_INIT
 
@@ skipping 622 matching lines @@
 
 DisableThreadInterruptsScope::~DisableThreadInterruptsScope() {
   if (thread() != NULL) {
     OSThread* os_thread = thread()->os_thread();
     ASSERT(os_thread != NULL);
     os_thread->EnableThreadInterrupts();
   }
 }
 
 }  // namespace dart